Charles kellner



(No'ModeL) 'CQKELLNER. A PROCESS OF PRODUCING HYDRATES OR OTHER SALTS 0F ALKALINE METALS.

No. 590,548. Pateflted sa -L21, 1897.

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UNITED STATES PATENT OFFICE.

CHARLES KELLNER, OF HALLEIN, AUSTRIA-HUNGARY.

PROCESS OF PRODUCING HYDRATES OR OTHER SALTS OF ALKALINE METALS.

SPECIFICATION forming part of Letters Patent No. 590,548, dated September 21, 1897.

Original application filed November 12, 1892, Serial No. 451,791. Divided and this application filed July 7, 1896. Serial No. 598,307. (No specimens.) Patentedin Germany August 17, 1892,1705. 70,007 and 73,224; in France September 26,1892, No. 224,557; in Belgium September 26, 1892, No. 101,506 in England September 26,1892,No.18,169; in Sweden September 26,1892,N0. 4,649; in Norway September 26,1892,No.3,045; in Italy September 80,1892, XXVII, 32,735, and LXIV, 341; in Austria-Hungary December 28, 1892, No. 47,195 and No. 71,840; in Russia May 28, 1894, No. 7,492,and in Switzerland July 14, 1895,11'0. 11,585.

' drates or other Salts of the Alkaline Metals,

(for which I have obtained the following foreign patents: In France September '26, 1892, No.-224,557; in Belgium September 26, 1892, No. 101,506; in England September 26, 1892, No.18,169; in Sweden September 26, 1892, No. 4,649; in Norway September 26, 1892, No. 3,045; in Italy September 30, 1892, XXVH, 32,735, LXIV, 341; in Germany August 17, 1892, Nos. 78,224 and 70,007; in Russia May 28, 1894, No. 7,492; in Switzerland July 14, 1895, No. 11,585, and in Austria-Hungary December 28, 1892, No. 47,195 and No. 71,840,) andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present application is a division of the application, Serial No. 451,791, filed by me the 12th day of November, 1892.

The invention has relation to the electrolytical decomposition of metallic salts and the recombination of the alkaline metals obtained by such decomposition with other elements to produce hydrates and other compounds.

My invention has in view,primar-ily,the production ona commercial scale and in a practically continuous manner of the alkaline hydrates or other salts of the alkaline metals, first, by decomposing the metallic salt electrolytically in the presence of a mercury cathode, so as to produce an amalgam, and, secondly, decomposing the amalgam and effecting the unition or combination of the alkaline metal with oxygen and other elements to produce hydrates or other combinations of the alkaline metal.

Many attempts have hitherto been made to utilize a mercury cathode in processes having the same object in view, but they have all failed owing to the difficulty in decomposing the amalgam so formed, as it is only very slowly decomposed by contact with liquid reagents, such as water, he. The removal of the alkaline metal from the mercury is not thus fully accomplished in the same unit of time as the absorption of the metal from the electrolyte into the mercury, so that the mercury becomes continually richer and richer in the alkaline metal during the working of the process until finally further progress is prevented by the formation of hypochlorites or similar salts in the electrolytical cell and by interruptions due to the butter-like c011- sistency which the mercury assumes after absorption of too much of the alkaline metal. I have now succeeded in overcoming these difficulties and have discovered a processby which electrolysis of salts of the alkaline metals becomes commercially possible by means of a secondary reaction, which can be brought about by means hitherto unknown.

This process is as follows: The amalgam having been formed by the electrolysis is brought into contact with the liquid which is to react on the alkaline metal, and an elec trode is introduced which is out of circuit with and is independent of the current employed in the formation of the amalgam. Un-

der these circumstances the amalgam becomes the soluble electrode (zinc pole) of a galvanic element, and the chemical energy resulting from the formation of the hydrate (or other salt) is converted into electricity. The current thus generated causes a rapid separation of the alkaline metal from the mercuryby short-circuitin g the amalgam with the independent electrode introduced into the separating vessel.

It is well known that an alkaline-metal amalgam forms agalvanio'elementwhen it is connected with a suitable electrode and brought into contact with a liquid reagent, and it has even been proposed to utilize this property for the storage of electricity for accumulators. It has also been proposed to decompose the amalgam by means of the same current which forms it by so connecting up the primary electrolytic decomposition-cell and the secondary cell wherein the amalgam is decomposed in the same circuit that the current passes first from the dynamo or other source of electricity by the main anode through the primary electrolyte to the mercury, (which thus acts as an intermediate cathode,) through the mercury into the secondary cell, (where the mercury thus becomes an intermediate anode, so that the mercury thus acts as a bipolar electrode in the main circuit,) and thence through the oxidizing solution to the principal cathode, which is in the oxidizing liquid of the secondary cell. In this manner the alkaline metal is reacted upon in the secondary cell and separated from the mercury; but the process constituting the present invention differs materially from those referred to and all others, as will appear from the following considerations: First, the electricity under my process, generated in the galvanic cell, is not stored and is not intended to be used for any outside purpose, but is short-circuited, so that the amalgam can rapidly be decomposed. The mercury during the whole operation contains only small quantities of the alkaline metal and acts as a conveyer for the alkaline metal from one cell to the other. The formation of the final product thus keeps pace with the original electrolysis, which is of great importance.

In processes hitherto proposed the immediate object has been the electrolytic production of a strong amalgam. The immediate object of my invention is, on the contrary, the rapid decomposition of the amalgam, so as to keep the alkaline metal in-the mercury at the lowest possible point. I do not employ the main current from the dynamo for this purpose, as has been previously proposed, but I use instead the current generated in a galvanic circuit by the action on the amalgam itself of the liquid reagent, which produces the required final alkaline product.

In order to render my invention well understood, so that it can be utilized by any one skilled in the art, I shall now describe the process more specifically, taking as an example sodium chlorid as the electrolyte from which the amalgam is to be produced and sodium hydrate and chiorin as the final product to be obtained.

In the accompanying drawings a suitable apparatus for the purpose is illustrated. This consists of a vessel so arranged that the two separate functions-21 e., the production of the amalgam and the decomposition of the sameare performed in two separate compartments or cells.

In said drawings, Figure 1 is a vertical sectional view of such apparatus, and Fig. 2 is a similar view of a modified form of the same.

As illustrated in Fig. 1, a vessel L is divided by a layer of mercury B into two parts, which can only communicate electrically with each other through this mercury. This can be eitected, for instance, as shown,'by cementing into the vessel L a clay cell A, having a very narrow slit-shaped interior filled with mercury, the arrangement being such as to prevent mingling of the two liquids at the opposite ends of the cell and having the mer cury opposed as a cathode to the carbon electrode H. These liquids are a solution of common salt, which is placed in one compartment, serving as the primary cell'and having the mercury opposed as an anode (zinc pole) to the cathode I, and water, which is placed in the other compartment, serving as the secondary cell. The water may be mixed with sodium hydrate for the purpose of increasing its conductivity at starting.

The apparatus may also be arranged, as shown in Fig. 2, so that the water floats on the mercury, in which case the clay cell A is enlarged at the top, so as to receive the third electrode I and the water necessary for decomposing the amalgam. In this case the electrode I is connected to the mercury below by an insulated conductor 1, as shown.

The main current from the dynamo or other source of electricity passes into the solution of comm on salt through a carbon electrode H, provided with a bell J, for carrying off chlorin, and passes out again through a wire G,

immersed in the mercury B. Into the water dilute solution of soda in the secondary cell dips an electrode I, which is connected by a bent conductor 1 with the mercury. The mercury or the metal (sodium) separated thereon and amalgamating therewith thus constantly forms with this third electrode I and with the intermediate soda solution a shortcircuited element. If now a current be sent ICC through the solution of common salt, chlorin will be separated at the anode H and sodium at the cathode B, the sodium becoming absorbed by and amalgamated with the mercury. This amalgam is at the same time the soluble electrode of the secondary galvanic cell, in which, since it is short-circuited, the water is decomposed and a violent formation of sodium hydrate takes place with generation of heat, whereby the sodium separated from the solution of common salt is at once withdrawn from the sphere of action of the primary cell and an electric current set up in the secondary cell. Consequently since diffusion between the two cells is impossible the decomposition of common salt in the primary cell will continue to take place without interrupt-ion, while the solution of sodium hydrate in the secondary cell continues to become richer. The mercury thus consti tutes the cathode for the primary electrolytic cell, and also at the same time the soluble electrode for the secondary galvanic cell.

The distinctions between my process as thus described and the processes hitherto practiced, proposed, or attempted are very important. If the amalgam is only in simple contact with the water and no electrolytic action takes place, the separation of the alkaline metal 590,548 I i 3 i from the amalgam occurs with extreme sluggishness and so slowly that for complete removal of the alkaline metal the contact must last for many hours, which of course makes requisite the employment of so great a quantity of mercury that the economic advantage of electrolysis over chemical processes for the production of alkaline hydrates or other alkaline salts becomes wholly illusory. If the mercury in the primary or electrolytic cell is not almost completely freed from the alkaline metal, the amalgam tends to become richer and richer in alkaline metal, and thus the counter-tension in the primary electrolytic cell is proportionately increased, and

therefore the necessary power for a unit of product increases in the same degree, for the mercury acts as an accumulator charged with electricity just in proportion to the amount of the alkaline metal present and raises the tension necessary for the decomposition to the full extent of the work which it could do as the soluble electrode of a galvanic element formed by the amalgam in connection with the electrolyte and the electrode,which serves as the primary anode; but by short-circuiting or galvanically connecting the mercury with the electrode in the oxidizing liquid of the secondary cell while it still contains very little alkaline metal the dissociated ions of the already-formed final product in the secondary cell are enabled to give up their charges of electricity at once, and so fresh alkaline metal is immediately taken up from the amalgam to form fresh ions in the solution of the final product, which again immediately give up their electricity to the galvanic circuit, &c. In this manner the alka line metal is continually exhausted from the amalgam in a positive manner and the mercury is continuously regenerated, so that in the carrying out of my invention the mercury in the electrolytic cell is constantly kept nearly free from alkaline metal, whereby the counter-tension (due to the tendency to form a galvanic element with the primary anode) is materially reduced. It is thus clearly demonstrated that I immediately form a galvanic element of the amalgam as fast as it is formed, which element by its own working rapidly destroys the amalgam which creates it, and thus instantly restores the mercury to the condition most suitable for taking up more alkaline metal in the primary electrolytic cell.

Having described my invention, 1 claim-- The method of producing hydrates or other salts of the alkaline metals, which consists in forming at one point, a given quantity of amalgam by electrolysis of a solution of a suitable salt in presence of a mercury cathode, and simultaneously oxidizing a substantially equivalent quantity of the alkaline metal contained in said amalgam at another point, by constituting the latter the anode (zinc pole) of a' galvanic cell containing a liquid reagent and a cathode electronegative to the amalgam and short-circuited therewith.

In testimony whereof I affix mysignature in presence of two witnesses.

CHARLES KELLNER. Witnesses:

SELDEN BACON, O. O. SEMPLE. 

